Hes been pushing this idea that American made 4.7 motors develop piston slap but the Japanese made 4.7 doesn't. Based on comments from a few mechanics. My truck has 230k on it, no problems and I don't baby it.

Piston slap in a Toyota V8? Maybe, plausible, possible.....but very rare. I've known several friends, co-workers, and had 2 company trucks, all Chevy's, that sounded like a Farmall until they heated up. Once warm they were silent. This all has to do with the tolerance being taken up as the piston expands. My last Chevy 5.3 company truck sounded like my Ford 7.3 .

Chevy V8's seemed to be plagued by this for years, I believe it's actually still a problem. But Chevy doesn't call it a problem, it's "inherent to their design and manufacturing practices". The Ford 5.4 was also hit-or-miss for slap.

Some high performance MX bikes with very short-skirt pistons have slap. But this is accepted and it's considered normal. These are also bikes that are pulled apart every 50 hours for rebuilds. I wouldn't accept any amount of slap in a modern vehicle engine.

I've had two gm 5.3 engines with piston slap. One developed early the other later. First one had 150k when I sold it and the other 226k. Neither burned oil or had issues related to the piston slap. I've known several others with 5.3 and piston slap along with a few fords. Never heard of it being an issue, but not saying its acceptable either.